'80 No Spark Problem

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socalfiver
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Location: Los Angeles, CA

'80 No Spark Problem

Post by socalfiver »

I've narrowed my no-start problem to No Spark.

I'm getting voltage to the + side of the coil with the key on. The coil checks out good when I run it in my other car.

I was leaning toward the Pulse Transmitter in the distributor. I bought a distributor from an '81 at the salvage yard, swapped it in and still no spark. Is there a tried and true method for testing it? What about the pickup wires to it? Could the pickup wire be broken internally? Where to test for continuity?

Is there a method for testing the Bosch ignition unit on the inner right fender near the right headlight?

Can anyone think of anything else I should check?

All help and advice is greatly appreciated.
"Get it while you can." -Janis Joplin

1980 528i Automatic, "Frau Blucher"
1982 BMW R100RS
1982 633csi 5 speed
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Peter Florance
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Re: '80 No Spark Problem

Post by Peter Florance »

socalfiver wrote:I've narrowed my no-start problem to No Spark.

I'm getting voltage to the + side of the coil with the key on. The coil checks out good when I run it in my other car.

I was leaning toward the Pulse Transmitter in the distributor. I bought a distributor from an '81 at the salvage yard, swapped it in and still no spark. Is there a tried and true method for testing it? What about the pickup wires to it? Could the pickup wire be broken internally? Where to test for continuity?

Is there a method for testing the Bosch ignition unit on the inner right fender near the right headlight?

Can anyone think of anything else I should check?

All help and advice is greatly appreciated.
The ICM (ignition control module) is mostly likely the problem. I've opened them and repaired bad solder joints.

Whack it moderately with rubber mallet while cranking and see if it catches at all.

Of course you could buy a used on from another SoCal e12 owner pretty cheap as well.



Me, I'm on the humid coast, so not as much help.
Peter Florance
First Fives.Org - The E12 Registry
1981 E-Street Prepared Euro BMW 528i w/3.5L & Megasquirt Fuel Injection
http://www.firstfives.org
mailto:peter@firstfives.org
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socalfiver
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Joined: Wed Jul 21, 2010 12:31 pm
Location: Los Angeles, CA

Post by socalfiver »

Thanks for the advice, Peter. I pulled off the ICM this morning and carefully desoldered/disassembled it. It smelled like burnt electronics. Sure enough, along the top edge of the backside of the circuit board was not a broken solder joint, but a burn in the circuit board that ran through one of the paths. I lumped the break with a small piece of wire.

The car now sputters (hey, waaay better than nothing!!), but will not start and run. When I verify spark with the timing light, it is not consistent. it is definitely sparking now, but not as often as it should be.

It looks like my ignition wires have been replaced with suppression wires. Would that, combined with resistor caps and resistor plugs, be enough to cause the inconsistent sparking?
"Get it while you can." -Janis Joplin

1980 528i Automatic, "Frau Blucher"
1982 BMW R100RS
1982 633csi 5 speed
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socalfiver
Posts: 229
Joined: Wed Jul 21, 2010 12:31 pm
Location: Los Angeles, CA

Post by socalfiver »

IT'S FIXED!!!!


The Salvage Yard gods are smiling on me. Found a distributor yesterday. Went to a different salvage yard today, there was a beautiful 633 that had an ICU and a near-new, amazing set of plug wires. The wires were so nice, it made me realize how cheap the ones on my car were. Set of wires and ICU cost me $20. What a deal!

Thanks to all for helping me get the problem tracked down and fixed.

it's stressful to buy a non-running car, but I'm happy to report that the transmission, brakes and steering all work!! It's driveable!

There was some white smoke on startup, but it dissipated quickly. I'll run a few tanks of gas through before I attempt to get it smogged.
"Get it while you can." -Janis Joplin

1980 528i Automatic, "Frau Blucher"
1982 BMW R100RS
1982 633csi 5 speed
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